Coupling



Aug. 2, 1966 R. JANSSEN ETAL COUPLING 2 Sheets-Sheet 1 Filed June 15,1964.-

FlG./O F/G.

FIG. 9

FIG. 8

g- 2, 1956 R. JANSSEN ETAL 3,263,452

COUPLING Filed June 15, 1964 2 Sheets-Sheet 2 g i 7" 1 v 1 I RICHARDJANSSEN THEODOR BURDELSKI fi -.11 KURT VO/HS INVENTOR.

United States Patent 3,263,452 COUPLING Richard Janssen, TheodorBurdelski, and Kurt Voihs, Dusseldorf, Germany, assignors to Ferroplast,Theo. Bnrdelski & Co., Dusseldorf, Germany, a corporation of GermanyFiled June 15, 1964, Ser. No. 375,050

Claims priority, application Germany, June 14, 1963,

14 Claims. (Cl. 643ti) This invention relates to a coupling and, moreparticularly, to apparatus arranged to connect rotatable shafts togetherfor the transmission of torque therebetween.

Torque-transmitting couplings have been made in the past in manydifferent designs and for many purposes. In all of these designs,certain essential basic problems must be solved. Generally speaking,these couplings have used torque-transmitting keys lying in grooves inthe coupling housing. The formation of these grooves has resulted in aweak section in the housing and this has been a limiting factor intorque transmission. When large forces with corresponding high rates ofrevolution are encountered, the construction of couplings of this kindhas been especially difficult. To eliminate these difliculties,designers have used tough alloy steels for the coupling housing whichencloses the keys and they have also used light metal for the keys toreduce centrifugal force. However, despite the use of such special materials, the transmission of large forces at high rates of rotationdictated coupling dimensions that were quite large and the manufactureof such couplings was not only more expensive but also presented newproblems in the technique of fabrication. These and other difficultiesexperienced with the prior art devices have been obviated in a novelmanner by the present invention.

It is, therefore, an outstanding object of the invention to provide acoupling wherein the problem of small housing cross-section due to theformation of axial grooves has been eliminated.

Another object of this invention is the provision of a coupling capableof transmitting high torques at high rates of rotation but whose bulk isnot unduly large.

A further object of the present invention is the provision of a couplingcapable of high force transmission which is relatively inexpensive tomanufacture.

It is another object of the instant invention to provide a couplingwhich is simple in construction, inexpensive to manufacture, and whichis capable of a long life of useful service with a minimum ofmaintenance.

It is a further object of the invention to provide a coupling Whoseparts are readily replaceable in the event of damage or wear.

With these and other objects in view, as Will be apparent to thoseskilled in the art, the invention resides in the combination of partsset forth in the specification and covered by the claims appendedhereto.

The character of the invention, however, may be best understood byreference to certain of its structural forms as illustrated by theaccompanying drawings in which:

FIG. 1 is an end view of a coupling embodying the principles of thepresent invention,

FIG. 2 is an end view of the outer housing of the coupling,

FIG. 3 is a sectional view of the housing taken on the line III-III ofFIG. 2,

FIG. 4 is an end view of a locking element associated with the coupling,

FIG. 5 is a top view of the locking element,

FIG. 6 is a sectional view of a liner taken on the line VI-VI of FIG. 7,

FIG. 7 is a plan view of the liner,

FIG. 8 is an end view of a gripper,

FIG. 9 is a side view of the gripper,

FIG. 10 is an end view of a modified version of the pp FIG. 11 is a sideview of the gripper shown in FIG. 10,

FIG. 12 is a sectional view of an alternative form of coupling taken onthe line XII-XII of FIG. 13,

FIG. 13 is an end view of the coupling shown in FIG. 12, and

FIG. 14 is a sectional view of an alternative form of a sleeve.

In general, the present invention removes the aboverecited difficultiesby suggesting the elimination from the very beginning of the problem ofthe weakening of the material by not providing grooves for keys. Theinvention includes grippers and liners resting on the inside of acylindrical sleeve and tension means for creating a tangential tensionwhich presses the grippers and liners against each other and against theinner surface of the sleeve where they are kept in their positionsrelative to one another. Furthermore, the invention suggests thecreation of a tangential tension wherein several liners are locatedbetween grippers to act as tangential wedges, so that the tangentialtension can be created by pushing these liners against the inner wall ofthe sleeve.

Referring first to FIG. 1, wherein are best shown the general featuresof the invention, it can be seen that the coupling consists of a tubularsleeve 1 and a shaft end 8. The shaft end has a cross-section in theform of a cross and is inserted within the sleeve 1; it Will beunderstood, of course, that the shaft end could be a separate couplingmember which would be bolted to a shaft. The sleeve 1 is provided at itsends with inwardly-directed annular flanges 2 and 3. One of the twoflanges has a slot 2a formed at one location. Grippers 5 formed of anelastomer, such as butadiene, are arranged in pairs on the inside wallof the sleeve 1; these grippers are opposite one another and are alwaysapproximately the same distance from each other. Between each pair ofgrippers 5 are positioned two liners 6 also formed of elastomermaterial. In the area of the slot 2a provision is made for a tensionmeans, such as a pressure member 4, which can be inserted through theslot 2:: as the last element going into the inside of the sleeve as soonas the grippers 5 and the lining 6 are in position on the inside wall ofthe sleeve 1. As is shown in FIGS. 4 and 5, the pressure member 4 can beformed as two matching wedges 4a and 4b which together have the generalshape of a rectangle in plan view. The surface of each gripper 5 ispartially curved, but this curvature merges into fiat surfaces Saagainst which the corresponding side faces of the neighboring liners 6lie. The front edges of the curved surface of the grippers 5 are lightlybeveled, as can be seen from FIGS. 8 and 9 to permit easy insertion ofthe shaft end 8 into the sleeve between the grippers 5. The grippers canalso be designed in a spherical form as shown in FIGS. 10 and 11.

In place of the flanges 2 and 3, it is possible to provide grooves inthe surface of the sleeve into which snap rings may be inserted to servethe same purpose as shown in FIG. 1A.

Referring to FIGS. 12 and 13, it can be seen that the invention can alsobe formed in such a way that the special pressure member 4 can beomitted. By doing so, the coupling becomes even more simple and aspecially designed tension wedge does not have to be provided. In thiscase, the tubular sleeve is designed as a socket 9 in which grippers 10are arranged. Between these grippers are positioned liners 11. In orderto lock the grippers 10 and the liners 11 against slipping in the socketwithin the range of the permissible load, these parts are made from anelastoruer material, such as butadiene, and are pressed into the socket9 in an elastically-deformed condition. The tangential forces resultingfrom the elastic deformation are so great that the grippers 10 and theliners 11 are pressed against the inside wall of the socket 9 and arenot able to slip, whereupon special tension and securing elements arenot necessary, as was true in the clutch shown in FIG. 1. A torqueelement 13 having notches 12-which mate with the grippers 10 and theliners 11 can be inserted into the sleeve and the clutch is ready foroperation.

The operation and advantages of this invention will now be readilyunderstood in view of the above description. Before the presentinvention, it was necessary to fabricate clutches with considerableexpenditure of material and labor. In such a case, keys engaged withgrooves which had to be milled into the cylindrical sleeve or housing ofthe coupling at considerable expense. In addition, this operation led tomuch weakening of the material cross-section. Because of the milling ofthe grooves for inserting the keys and, therefore, because of theweakening of the material cross-section, these old-type clutches had tobe made very large, especially when high torsion moment-s were to betransmitted and when high speed was required. By using materials of highstrength, the dimensions of the coupling could be kept small, but suchmaterials have been considerably more expensive and they have made themachining much more difficult because of their greater toughness whichmakes for a more expensive machining operation.

In the present case, because of the omission of the milled grooves forthe keys, the coupling constructed in accordance with the presentinvention requires only a simple thin-walled sleeve made from steel orother material, such as light metal. This sleeve can be fabricated byuse of the simplest methods, since it requires only surface machiningand there are no difficulties to be encountered by necessary heattreatments. Therefore, the manufacture of the cylindrical sleeve is veryinexpensive, even though it may be made of high tensile-strengthmaterials. In comparison with the previously known couplings and theirsleeves, the material expenses and the machining and transportationcosts are very small.

It is necessary to insert the grippers and the liners 6 into the sleeveand in place of one of the liners 6 the pressure member 4 is driventhrough the slot 2a between the neighboring grippers 5 on one side andthe liner 6 on the other side. By driving the member 4 inwardly, atangential force is created which presses the grippers 5 and the liners6 against the inside wall of the sleeve, thus obviating the danger ofslippage. The pressure member 4 can be made from steel, metal, orplastic or made out of a combination of these materials and can besecured additionally by a screw 7, although this securing means isusually not needed because of the high tangential forces.

The insertion of the shaft 8 into the opening of the cylindrical sleeve1 and the elements 4, 5, and 6 in place is very simple. The exchange ofdamaged or worn grippers or liners is also simple and presents nodiificulty, this being accomplished by loosening the pressure member 4at any given time.

One of the advantages of a coupling made in accordance with theinvention (particularly the one shown in FIGS. 12 and 13) is that theclutch is secured against overload without having any intricatemechanism. In this case, the selection of the tangential forces broughtabout by the elastic deformation of the elements and 11 take intoaccount the fact the friction between the elements and the sleeve 9 mustcorrespond to the maximum load permissible. In case the maximum load isexceeded, then a slippage movement is created between the grippers andthe liners, on the one hand, and the sleeve, on the other hand, becausethere is no positive securing element built into the sleeve to preventthe turning of the grippers and liners.

It can be seen from an examination of these couplings that a number ofspecial advantages arise as compared with the previously knowncouplings, especially in regard to the smaller fabricating costs, thelower weight, and the smaller dimensions. In spite of smaller dimensionof the coupling, it is possible to transmit higher torque at higherspeed. It also includes an additional security against an overload whichcould previously only have been obtained by use of special designelements. Finally, the individual parts of the clutch can be removedwithout any particular difiiculty and in case of damage can be exchangedvery easily.

It is obvious that minor changes may be made in the form andconstruction of the invention without departing from the material spiritthereof. It is not, however, desired to confine the invention to theexact form herein shown and described, but it is desired to include allsuch as properly come within the scope claimed.

The invention having been thus described, what is claimed as new anddesired to secure by Letters Patent 15:

1. A coupling consisting of a sleeve and a shaft lying Within the sleevewith grippers between the sleeve and shaft which are movable in adirection parallel to the clutch axis and are exchangeable,

distinguished by the fact that liners are arranged between the grippersand rest on the inside wall of the sleeve, with the assistance oftension devices creating tangential tension which press against eachother and against the sleeve wall, and are retained in that positionrelative to each other.

2. A coupling as recited in claim 1, wherein the tangential tension iscreated by a liner which is formed as two tangential wedges.

3. A coupling as recited in claim 1, wherein the tangential tension iscreated by the elastic deformation of the liners and grippers to bebrought into contact with the inside wall of the sleeve.

4. A coupling as recited in claim 3, wherein the cylindrical sleeve withthe grippers and the liners is designed as a clutch socket to be slippedonto a torque element.

5. A coupling as recited in claim 4, wherein the cylindrical sleeve isequipped with annular flanges.

6. A coupling as recited in claim 5, wherein one of the angular flangescontains a slot for insertion of the liners and grippers.

7. A coupling as recited in claim 4, wherein the cylindrical sleevecontains annular grooves at the ends for the insertion of snap ringsservings as securing elements in the axial direction.

8. A coupling as recited in claim 7, wherein the cylindrical sleeve ismade up of a metal and the grippers and liners are formed of anelastomer.

9. A coupling as recited in claim 8, wherein the torque element of theclutch is provided with the grooves and the gripper to form parts of theelement while located between them are individual liners which arepressed by axial and radial tension against the inside walls of thesurrounding ring.

10. A coupling as recited in claim 9, wherein the tangential tensioncauses the pressure of the grippers and of the liners against the sleeveto correspond to the transmission of the maximum tortional rotation andno positive securing elements are provided between these parts and thesleeve.

11. A coupling, comprising (a) a sleeve having on a cylindrical bore,

(b) a male element insertable in the bore and having axial recesses,

(c) an elastomer gripper in each recess engaging the surface of thebore,

(d) an elastomer liner between each pair of grippers engaging thesurface of the bore,

(e) a pressure member acting between a gripper and a liner and pressingsideways against them to produce elastic deformation thereof.

5 6 12. A coupling as recited in claim 11, wherein the References Citedby the Examiner 55:21:15; member consists of a pair of cooperating wedgeUNITED STATES PATENTS 13. A coupling as recited in claim 11, wherein the2,160,445 5/1939 Spicer 64-27 pressure member consists of the last ofthe grippers and 5 FOREIGN PATENTS liners to be inserted.

14. A coupling as recited in claim 11, wherein an inwardly-directedflange is provided at each end of the bore and a slot is provided in oneof the flanges, the slot pro- I viding for the insertion of thegrippers, liners, and the 10 MILTON KAUFMAN Exammer' pressure member.HALL C. COE, Examiner.

195,700 2/1958 Austria. 929,544 6/1955 Germany.

1. A COUPLING CONSISTING OF A SLEEVE AND A SHAFT LYING WITHIN THE SLEEVEWITH GRIPPERS BETWEEN THE SLEEVE AND SHAFT WHICH ARE MOVABLE IN ADIRECTION PARALLEL TO THE CLUTCH AXIS AND ARE EXCHANGEABLE,DISTINGUISHED BY THE FACT THAT LINERS ARE ARRANGED BETWEEN THE GRIPPERSAND REST ON THE INSIDE WALL OF THE SLEEVE, WITH THE ASSISTANCE OFTENSION DEVICES CREATING TANGENTIAL TENSION WHICH PRESS AGAINST EACHOTHER AND AGAINST THE SLEEVE WALL, AND ARE RETAINED IN THAT POSITIONRELATIVE TO EACH OTHER.